Co-occurrence of tree species at fine spatial scale in a woodland cerrado, southeastern Brazil

Abstract

Species co-occurrence at fine spatial scales is expected to be nonrandom in relation to species phylogenetic relatedness and functional similarity. On the one hand, closely related species that occur together and experience similar environmental conditions are likely to share phenotypic traits due to the process of environmental filtering. On the other hand, species that are too similar are unlikely to co-occur due to competitive exclusion. We surveyed a woodland cerrado, southeastern Brazil, to test whether co-occurrence in tree species shows functional or phylogenetic structuring at fine spatial scale. Searching for correlations between an index of species co-occurrence and both functional trait differences and phylogenetic distances, we provided evidence for a predominant role of environment filters in determining the co-occurrence of functionally similar tree species in cerrado. However, we did not find any effect of phylogenetic relatedness on tree species co-occurrence. We suggest that the phylogenetic relatedness of co-occurring cerrado tree species did not present a pattern, because the species functional traits were randomly distributed on the phylogeny. Thus, phylogenetic relatedness and functional similarity do not seem to limit the co-occurrence at fine spatial scale of cerrado tree species.

Woody plant species co-occurrence in Brazilian savannas under different fire frequencies

“…For a woodland cerrado in southeastern Brazil, we also did not find any pattern of species co-occurrence in relation to species phylogenetic relatedness (Silva and Batalha, 2009). The absence of a phylogenetic pattern, in these cases, may be due to random distributions of some functional traits in the phylogeny of species (Webb et al, 2002;Silvertown et al, 2006).…”

“…In some cases, the evolution of traits is indistinguishable from random (Silvertown et al, 2006), and a clear pattern of phylogenetic clustering or overdispersion may not emerge (Silva and Batalha, 2009). A widespread phylogenetic signal has been observed in plant traits related to environmental tolerances (i.e., light, soil moisture, and pH, Prinzing et al, 2001).…”

“…However, the functional similarity of cooccurring species still remains inconclusive (see Leibold, 1998 for references). Recently, we observed that the environmental filters might determine the co-occurrence of functionally similar tree species in cerrado (Silva and Batalha, 2009). Here, we tested whether annual fire frequencies change the pattern of local cooccurrence of cerrado woody species at a fine spatial scale, taking into account the nearest neighbours.…”

The intersection of ecological risk assessment and plant communities: an analysis of Agrostis and Panicum species in the northeastern U.S.

“…Co-occurrence was computed for A. stolonifera and P. virgatum using the formula: (Schoener 1969, Silva andBatalha 2009). In this equation, C is the co-occurrence value of the ith and hth species, and p is the proportion of occurrence of the ith or hth species in the jth community (transect).…”

How does resprouting response differ among three species of savanna trees and in relation to plant size?

“…Nevertheless, similar results relating the level of trunk fire injury and basal resprouting would probably be obtained for other species, as we found for two tree species in this study. It has been argued that Cerrado woody species occurring together and under similar environmental conditions would have close-related phenotypic traits (Silva & Batalha 2009). However, burning resistance strategies depend on historical fire regimes (especially fire frequency) that can lead to many different plant responses, as for example bud protection and bark thickness, not evaluated here and that still need to be better understood for Cerrado tree species.…”